FTPS/SFTP server certificate not working

Question

I have to use FTPS for file transfer. Hence, my requirement is to perform ftp server certificate validation. Currently, we have generated user signed certificate of ftp sever machine using openSSL, The resulting file is cacert.pem.

Its format is:

-----BEGIN CERTIFICATE-----
----------------------------------
-----END CERTIFICATE-----

I am using SecureFileTransferClient and server validation

client.loadSSLServerValidation(rootCert);

I have passed the ftp server machine certificate to above method. 

Its throwing me exception as below

Server certificate could not be validated. (use SSLFTPCertificateException.printCertificates to view certificates.).

1. Will I be able to use user sign certificate?
2. If yes, what is format of certificate?
3. Do I need to install that certificate on ftp server machine?

Answer 1

The user signed certificate must be installed on the server to be of any use. The server sends the certificate to the client which verifies it using the PEM file supplied, which can either contain 1) the CA certificate the server cert was signed with, or 2) the actual server certificate. More information in the User Guide here.